The total number of treatments will vary from patient to patient, however likely timeframes specific to your case will be discussed with you.
It is worth keeping in mind a general rule of thumb especially for chronic conditions the longer you have had the problem the longer it will take to resolve it. If you have had a problem for several years it would not be unrealistic for it to take 3-6 months to resolve. However as a part of treatment you will be given guidelines that help you to determine the effectiveness of the the treatment you are receiving.